Comparison between different radiographic methods for evaluating the flexibility of scoliosis curves

Abstract

OBJECTIVE: To compare different radiographic methods of spine evaluation to estimate the reducibility and flexibility of the scoliosis curves. METHODS: Twenty one patients with Lenke types I and III adolescent idiopathic scoliosis (AIS) were included. Radiographic evaluations were made preoperatively on the orthostatic, supine decubitus with lateral inclination to the right and left and supine positions with manual reduction, with support in the apex of each curve on the X-ray table. On the day of surgery, when the patient was anesthetized, radiography was taken with longitudinal traction through divergent forces, holding under the arms and ankles, and with translational force at the apex of the deformity for curve correction. After one week, a post-operative radiography was performed in orthostatic position. RESULTS: The correction and flexibility of the main thoracic and thoracic/lumbar curves were statistically different between the supine radiographs, manual reduction, modified traction under general anesthesia, lateral inclination and postoperatively. The modified maneuver for traction under general anesthesia is the one which showed greater flexibility, besides presenting higher radiographic similarity to postoperative aspects. CONCLUSION: Among the radiographic modalities evaluated the study under anesthesia with traction and reduction showed better correlation with postoperative radiographic appearance. Level of Evidence IV, Case Series.

Evaluating the Rotation Correction of the Main Thoracic Curve in Severe Adolescent Idiopathic Scoliosis: Bending and Traction vs. Fulcrum – A Preliminary Report

“…It should be noted that the after-general-anesthesia orthopedic effect was better at the traction radiograph than at the fulcrum radiograph when the interference of muscles and soft tissues was ruled out. This was echoed by studies of Rodrigues et al [ 17 ] Therefore, the orthopedic force applied in the longitudinal direction can still be regarded as superior to that in the cross-sectional direction. The reason why the flexibility achieved at the normal traction radiograph is not so good as at the fulcrum radiograph may be that the actual orthopedic force applied to the spine is smaller than the applied external force due to muscle tension during the process of traction.…”

May bending radiographs be replaced by recumbent CT scans in patients with adolescent idiopathic scoliosis?

“…However, it has also been shown that selection of lowest instrumented vertebra based on traction radiographs leads to an increased frequency of decompensation of the non-instrumented lower spinal segments [10,17]. The available data show that none of the common types of BR is superior to the others [6,8,10,[15][16][17].…”

“…Furthermore, BR allows assessing the possible potential for correction of the deformity by surgery [6,7]. There are different types of bending radiographs: Push-prone radiographs (PPR) [8], fulcrum bending radiographs [6], supine side-bending radiographs [9], and radiographs with traction under General Anesthesia [10]. All types of BR lead to an additional amount of exposure to radiation for the patient.…”

Comparison Between Radiographic Methods of Measuring Flexibility in Scoliosis

“…As regards the L curve, we noted that bending presented lower values than traction, (Table 3) a finding similar to the study by Watanabe et al, 15 which obtained a statistical difference when the initial Cobb angle was less than 50 o , as in our study in which the mean L curve found was 49.1 o . In the traction under anesthesia technique described by Davis et al, 6,8 in which muscle relaxation removes traction discomfort for the patients, a better result was obtained. In this study it was observed that this method had a greater absolute decrease in the mean curve, coinciding with Davis et al and Hamzaoglu et al, 10 (Tables 1, 2 and 3) being always less than bending and traction and closer to the postoperative values.…”

“…2 In their classifications, King 3 and Lenke 4 highlighted the importance of the flexibility of the curves in the radiographical examination, formulating the concept of curve structurality and defining it as one of the most important parameters for surgical planning, responsible for the choice of arthrodesis levels and the number of corrective osteotomies. [5][6][7][8][9] Flexibility can be analyzed by several methods: bending in the standing or dorsal horizontal decubitus positions, fulcrum bending, traction, traction under general anesthesia, among others. [5][6][7][10][11][12] Currently, bending radiographs are considered the gold standard for flexibility assessment, because they are easy to perform and are one of the parameters included in the classifications.…”